During the Achaemenid Persian Empire, around 600 BC the Persians first began to use the abacus.

During the first invasion, Thrace, Macedon and the Aegean Islands were added to the Persian Empire, and Eretria was duly destroyed.

During this period, Athens and Sparta rose to a position of political eminence in Greece, and their rivalry in the aftermath of the Persian wars brought Greece into renewed internal conflict.

During this time, Jews have experienced slavery, anarchic and theocratic self-government, conquest, occupation, and exile ; in the Diasporas, they have been in contact with and have been influenced by ancient Egyptian, Babylonian, Persian, and Hellenic cultures, as well as modern movements such as the Enlightenment ( see Haskalah ) and the rise of nationalism, which would bear fruit in the form of a Jewish state in the Levant.

During the second Persian invasion of Greece ( 480-479 BC ) Megara fought alongside the Spartans and Athenians at crucial battles such as Salamis and Plataea.

During the Persian Gulf crisis, Oman assisted the United Nations coalition effort.

During the war between the Scythians and the Persian Empire, the Scythians came to dominate the Neuri.

During the years 550 to 330 BC, coinciding with the sovereignty of the first Persian Empire over the Middle East area, especially the whole part of the Persian Gulf and some parts of the Arabian Peninsula, the name of " Pars Sea " is widely found in the compiled written texts.

During the end of the fourth millennium BC, the southern part of the Persian Gulf was dominated by the Dilmun civilization.

During the 7th century the Sassanid Persian empire conquered the whole of the Persian Gulf, including southern and northern shores.

During his reign the Roman eastern frontier underwent extensive re-fortification, including the construction of Dara, a stronghold intended to counter the Persian fortress of Nisibis.

During their rule they extensively invited, and received, a steady stream of Persian scholars, poets, jurists, architects, and painters.

During this time he published Histoire de Nader Chah ( 1770 ), a French translation of a work originally written in Persian by Mirza Mehdi Khan Astarabadi.

During his studies, he dedicated himself to mastering English — adding this language to the Persian, Turkish, Arabic and French, languages in which he was already fluent-so that he could translate the letters of ` Abdu ' l-Bahá and serve as his secretary.

During the Achaemenid period, Sogdiana and Bactria were part of the Persian empire.

During the first Persian invasion of Greece, he fought at the Battle of Marathon, and was possibly one of the 10 Athenian strategoi ( generals ) in that battle.

During the nineteenth and early twentieth centuries, the pearling industry thrived in the relative calm at sea, providing both income and employment to the people of the Persian Gulf.

During the Middle Ages, heliocentric models may have also been proposed by the Indian astronomer, Aryabhata, and by the Persian astronomers, Albumasar and Al-Sijzi.

* Middle East: During the Persian empire, Zoroaster, aka Zarathustra, founded Zoroastrianism, a dualistic philosophy.

* During the turmoil of the An Shi Rebellion, the Chinese seaport Guangzhou is sacked by Arab and Persian raiders.

During the closing stages of the Iran-Iraq War the United States Navy began conducting operations in the Persian Gulf to protect US-flagged ships from attack by Iranian naval forces.

During the Persian invasion of 480 BC it manned the second largest Greek fleet ( 60 ships ), but took no active part in the war.

During this period the Muslim world was a cauldron of cultures which collected, synthesized and significantly advanced the knowledge gained from the ancient Roman, Chinese, Indian, Persian, Egyptian, North African, Greek and Byzantine civilizations.

* During the process of Christianisation under Constantine, groups destroyed the images and sculptures expressive of the Roman Empire's polytheist state religion.

During his reign, Justinian sought to revive the Empire's greatness and reconquer the lost western half of the classical Roman Empire.

During his reign in Aquitaine, Louis was charged with the defence of the Empire's southwestern frontier.

During the Tulip Era ( 1718 – 1730 ), named for Sultan Ahmed III's love of the tulip flower and its use to symbolize his peaceful reign, the Empire's policy towards Europe underwent a shift.

During Late Antiquity, the office of quaestor sacri palatii existed, created by Constantine the Great, which functioned as the Roman Empire's senior legal official.

During the Ottoman Empire's domination of the Aegean Sea, the Turkish exonym for the island was " Santurin " or " Santoron ".

During Tsarist times the Ukrainian provinces of the Russian Empire were referred to as the Empire's breadbasket.

During the Empire's Formation Wars the Earth is once more hit hard, but is eventually incorporated into the Imperium as the " honorary capital.

During the mid-13th Century, the Empire's presence weakened in the Aare valley, forcing the local nobles to find allies to protect themselves.

During the Roman Empire's first 200 years, this tradition was common with Tiberius, Caligula, Nero, Trajan, Hadrian, Antoninus Pius and Lucius Verus all becoming Emperor through adoption.

During a succession dispute in 1360 between two rival lineages within the Mali Empire's royal bloodline, the Jolof became permanently independent.

During that conflict, Revan learned of the hidden Sith Empire's influence on the Mandalorians and realized that only a military offensive led by someone who understood the Sith would be able to repel them.

During the first half of the 11th century, the Liuticians participated in the Holy Roman Empire's wars against Piast Poland.

During the Ottoman Empire's reign on the island, which lasted from 1665 until 1895, Gavdos was known as Gondzo.

During these years Shah Ismail I suffered a large defeat when his large cavalry-based army was obliterated at the Battle of Chaldiran by the Ottoman Empire's new weapon, the matchlock musket.

During the reign of Eastern Roman Emperor Isaac I Komnenos, the single-headed eagle was modified to double-headed to symbolise the Empire's dominance over East and West.

During this time, he became acquainted with Dr. Valerie Cooper, a United States government official who was unaware of the Secret Empire's true nature or activities.

During the Late Bronze Age circa 2000 BC, they created an empire, the Hittite New Kingdom, which reached its height in the 14th century BC, controlling much of Asia Minor.

During the height of the Malenkov – Khrushchev struggle, Khrushchev actively fought for improvements in Soviet agriculture and the strengthening of the role of the Central Committee.

During the height of the reign of terror, David was an ardent supporter of radicals such as Robespierre and Marat, and twice offered up his life in their defense.

During the spin, the dancer kicks out to touch a tassel suspended between knee and waist height.

During and after the war, Kangol berets were the height of fashion.

During the height of collectivization, however, people identified as kulaks were subjected to deportation and extrajudicial punishment.

During the height of his power, Jumbe transported between 5, 000 and 20, 000 slaves through Nkhotakota annually.

During the height of its popularity, the website was receiving over 6 million hits per month.

During the 16th and 17th centuries, in particular at the height of its power under the reign of Suleiman the Magnificent, the Ottoman Empire was one of the most powerful states in the world – a multinational, multilingual empire that stretched from the southern borders of the Holy Roman Empire to the outskirts of Vienna, Royal Hungary ( modern Slovakia ) and the Polish – Lithuanian Commonwealth in the north to Yemen and Eritrea in the south ; from Algeria in the west to Azerbaijan in the east ; controlling much of southeast Europe, Western Asia and North Africa.

During the 16th and 17th centuries, at the height of the Empire, no other region would prove of more strategic and economic importance.

During the height of the Roman Empire, famous historians such as Polybius, Livy and Plutarch documented the rise of the Roman Republic, and the organization and histories of other nations, while statesmen like Julius Caesar, Cicero and others provided us with examples of the politics of the republic and Rome's empire and wars.

During the reign of Pope Innocent III, the papacy was at the height of its prowess.

During the height of its power in the 2nd and 3rd centuries BC, Meroe extended over a region from the third cataract in the north to Soba, near present-day Khartoum, in the south.

During walking, the center of mass reaches a maximum height at midstance while during running, it is at a minimum.

During the 8th century Wessex was overshadowed by Mercia, whose power was then at its height, and the West Saxon kings may at times have acknowledged Mercian overlordship.

During the height of Urartian power, irrigation canals and an artificial reservoir were built on Yerevan's territory.

During these several months, each new shoot grows vertically into a culm with no branching out until the majority of the mature height is reached.

During the height of the day, photosynthesis is at its peak, producing the highest levels of sugar in sap, making this the least ideal time of day to harvest.

During May and July 2009 several mountains were re-surveyed by the Munro Society to determine a more accurate height reading for those mountains which are known to be close to the 3, 000 ft figure.

During the height of the North American fur trade in the 18th and 19th centuries, many British and French-Canadian fur traders married First Nations and Inuit women, mainly First Nations Cree, Ojibwa, or Saulteaux.

During the height of the Indus valley civilization about 2000 BC, the Harappan colony now known as Shortugai was established near the lapis mines.

During the 1920s, specifically in 1928, the components of the Dow were increased to 30 stocks near the economic height of that decade, which was nicknamed the Roaring Twenties.

During this period in Spain and Latin cultures, women wore lace mantillas, often worn over a high comb, and in Buenos Aires, there developed a fashion for extremely large tortoise-shell hair combs called peinetón, which could measure up to three feet in height and width, and which are said by historians to have reflected the growing influence of France, rather than Spain, upon Argentinians.

During the height of hyperinflation in 1992 – 1993, the Central Bank actually tried to derail reforms by actively printing money during a period of inflation.

During the 19-minute flight, the Duke flew the aircraft at its scheduled en route height of 1, 000 ft.